Audio Database


ONKYO Integra M-508
240,000yen(around the 1986 time)

Stereo power amplifier which investigated the real phase (digital) amplifier stream composition which reproduces exact phase and sound field.

In order to keep the phase of an input signal from being confused, it is necessary to make it the speaker electric current from which the phase shifted not return to an amplification part. For this reason, the interference to an amplifier circuitry is eliminated by adding a power in phase transformer to an electric-current path.
The right-and-left independent-source scheme is adopted, and the phase response of amplifier is improved by carrying two power in phase transformers only for L/R Integra M-508.
Moreover, the common mode noise which invades from AC line is also eliminated by the power in phase transformer.

The power-source part of 4 transformer stream compositions which added the power in phase transformer only for L/R to the right-and-left power transformer,The power transistor of a triple push pull, the 10,000-micro F power-source part of large-sized capacitor x8, the direct power feeding by the shortest distance, etc. have realized high power.

In order to suppress a failure of Loule Bell which poses a problem with high power amplifier, the low distortion is realized by adopting a setups of the low-noise bias which adopted linear switching and light emitting diode, W sensing servo circuitry, etc.

The input terminal carries two lines, Direct and Variable.

The peek meter which can switch a meter range to two steps is carried.
ON/OFF of an illumination is also possible for this meter.

The polar attached-indicator power cord is adopted.

The right-and-left independent level controller with a high precision multi-brush is adopted.


Rating of a mode
Form Stereo power amplifier
<Amplifier part>
Output power (20Hz - 20kHz) 290W+290W (4ohm)
240W+240W (6ohm)
200W+200W (8ohm)
Dynamic power 690W+690W (2ohm)
460W+460W (4ohm)
270W+270W (8ohm)
THD 0.002% (at the time of 20Hz - 20kHz, 8 ohm, and an Output power)
Cross modulation distortion 0.003% (at the time of 70Hz:7kHz=4:1 and an Output power)
Power Band Width 5Hz - 100kHz (IHF-3dB, THD0.2%)
Gain 32dB
Frequency characteristic 1Hz-100kHz+0 -1.5 dB
Input sensitivity/impedance 1V/20kohm
SN ratio 124dB (an IHF-A filter, input short-circuit)
Dumping factor 140 (8 ohms, 50Hz)
Input terminal Variable: One line
Direct: One line
Output-terminal Speakers: Two lines
<Meter part>
Range switching x1 (0dB=200W)
x0.1 (0dB=20W)
Indicating range x1 range: 0.01W-500W
x0.1 range: 0.001W-50W
Indication precision 0±1dB
- 10±2dB
- 20±3dB
Speed of response 100microsec (-infinity->0dB)
Carriage-return velocity 1sec (0dB->-20dB)
AC outlet Power-switch un-interlocking.: One line, 100W
Power source AC100V, 50Hz/60Hz
Power consumption 500W (Electrical Appliance and Material Control Law)
Dimensions Width 465x height 187x depth of 426mm
Weight 25kg